[Behavior therapy of onchophagia and trichotillomania. Ethological and behavioral perspectives].

Emphasis is brought to similarities between informations collected from the study and treatment of patients suffering from nail biting and trichotillomania, by behavioural treatment and the concept according to which such troubles are "tics", learned responses which will become non adapted, present in a given situation, reinforced by time and progressively more resistant to extinction on the one hand, and ethological concepts which consider those behaviours as displacement of activity such as "grooming" in primates, ritual activities, free from nutritions activities, triggered by some attitudes and facilitated by the presence of fear affects, aggressivity or sexual drive.